Step by step motor and/or brake device

#The invention relates to a step by step motor and/or brake device, i.e. to a device which responds to a movement of controlled translation, by providing or by allowing a rotational movement; more precisely, in the device according to the present invention, said controlled translation is one of a series of reciprocating movements, a movement which produces or allows a fraction of rotation which is discontinuous. In particular, but not exclusively, the present invention applies to a step by step motor or brake, i.e. to a motor which responds, to an order which produces therein a complete translation (outward or inward travel), by providing or by allowing a partial rotation, of invariable magnitude and invariable direction.

#The present invention has then as an aim to provide a rotational device by controlled translation, which satisfies the requirements of practice, particularly in that it is reliable in operation, in that it may be constructed without requiring a great accuracy in the manufacture of its component parts, and in that the application of the movement of translation which controls it reliably produces or allows the partial rotation of determined magnitude and determined direction.

#The present invention has as an object a step by step motor and/or brake device by controlled translation, characterized in that it comprises essentially two assemblies disposed substantially coaxially about the same shaft, one or the other of the two assemblies may slide reciprocally under the action of said control along said shaft and the other assembly is secured against sliding along said shaft, one or the other of the two assemblies may rotate about said shaft while providing the desired rotation and the other assembly is secured against rotation about said shaft, one or the other of the two assemblies comprises at least one roller whose axis is perpendicular to said shaft, and the other assembly comprises at least an annular ring, in which at least one face perpendicular to said shaft carries at least one cavity, of which the surface is substantially the envelop of said roller whose base would roll over a cylindrical line forming a V-shaped hollow, symmetrical or asymmetrical, said controlled translation bringing into mutual contact said cavity and said roller, then causing said roller to roll over said cavity to the bottom of the V, which provides said desired rotation.

#The invention will be better understood with the complement of description which follows which refers to the accompanying drawings in which:

#FIGS. 1, 2 and 3 are three developed figures of the cylindrical line, with a single cavity and a single roller, in three successive operational phases, which illustrate the principle of the invention and its above described embodiment;

#FIGS. 4, 5 and 6 are three developed figures of the cylindrical line, with a plurality of cavities and a plurality of rollers, in three successive operational phases, which illustrate the principle of another embodiment of the invention, defined above;

#It will be readily understood however that these drawings and the corresponding descriptive parts are given solely by way of an illustration of the subject of the invention, of which they are in no wise to be considered a limitation.

#FIGS. 1, 2 and 3 are three figures, in three successive operational phases, of the cylindrical line, assumed split along a generatrix parallel to the general axis XX and developed flat, of the annular ring 1, with a V-shaped cavity 3 which may be symmetrical as shown and which cooperates with a roller 5. Of course, only the relative movements of the annular ring 1 and roller 5 count, and it is only for simplicity's sake that the annular ring 1 is here assumed fixed. In FIG. 1, the roller 5 is outside cavity 3. If the shaft of roller 5 is pressed down (or pulled), roller 5 descends (arrow F1) and contacts cavity 3 (FIG. 2), then roller 5 rolls over one leg of the V of cavity 3 and stops at the bottom of cavity 3 (FIG. 3): thus, the shaft carrying roller 5 has been brought into a predetermined angular position which may be adjusted by adjusting the angular position of annular ring 1. It is evident that by employing several cavities 3 in annular ring 1, and/or two annular rings 1 symmetrically positioned but staggered, a plurality of such pre-adjusted positions may be obtained. It is also evident that the shaft carrying roller 5 could be arranged not to slide on itself and that its predetermined angular position or positions would then be obtained by pulling (or pushing) the annular ring or annular rings 1 parallel to the general axis XX. Such structures permit the free rotation of a shaft and its positioning in predetermined angular positions.

#FIGS. 4, 5 and 6 are similar to the preceding FIGS. 1, 2 and 3 and concern another embodiment, defined above. The assembly sliding reciprocally along the shaft having an axis XX comprises two annular rings 1 and 2, which are each provided with a plurality of cavities 3 and 4, these cavities being identical to each other and consecutive in each annular ring, the two annular rings 1 and 2 being symmetrical and being, in relation to each other, staggered angularly by the half 7 of a cavity width or step 8. Cavities 3 and 4 are here in the shape of a completely asymmetrical V, i.e. with one leg or face 9 parallel to the general axis XX and with the other leg or face 11 forming an angle .alpha. (FIG. 4) with the general axis XX; this angle .alpha. is less than about 60.degree.; it is preferably equal to about 30.degree.. The frusto-conical rollers 5 are here equal in number to half the number of cavities 3 of annular ring 1 (or 4 of annular ring 2), but they could be equal in number or in another sub-multiple number or equal to 1, as already indicated and obvious, as well as the reverse arrangement of these two numbers. The operation is equivalent to that already described with reference to FIGS. 1, 2 and 3; with rollers 5 at the bottom of the cavities 3 of the annular ring 1 (FIG. 4), a downwards translation of annular rings 1 and 2 (arrow F3 of FIG. 5) brings faces 11 of cavities 4 of annular ring 2 in contact with rollers 5, then (arrow F4 of FIG. 6) causes these rollers 5 to roll over faces 11, which produces the desired rotation, by half a step 7 shown by arrow F5. When the reverse movement occurs (upwards) of annular rings 1 and 2, rollers 5 will still rotate half a step 7, but always in the direction of arrow F5. Thus it can be seen that the invention provides indeed a device responding to a controlled translation (equal to F3+F4 or opposed to F3+F4) by a rotation which is always equal (to half a step 7) and in the same direction (shown by arrow F5), i.e. a step by step device.